Accidents are a prevalent feature of working in the maritime industry. While studies have shown to what extent accidents and fatalities have occurred, the current research has generally been limited to commercial shipping. There is nearly no academic research focusing on the safety issues in the superyacht industry. This paper analyses the importance of promoting safety culture in the superyacht industry, the role of maritime legislation in maintaining safety and the role of Port State Control in ensuring all legislation is implemented. It aims to provide a critical examination of safety culture in the superyacht industry and evaluate the appropriateness for further measures to ensure safe working practices. It found out that while some superyachts do maintain an effective safety system, there remains almost 50% of the investigated fleet that do not promote the desired safety culture. It becomes evident that complacency and poor education contribute to the reduced and limited safety culture. The lack of education and awareness is demonstrated when the study shows individuals believing they maintain good safety practices but still admitting to taking various life-threatening risks.

The As sorption capacity of a natural Mn and Fe mineral-containing sample from the Iron Quadrangle province, Brazil, was investigated. A detailed mineralogical identification was obtained by combining X-ray diffraction analyses (with Rietveld refinement), X-ray fluorescence spectroscopy, optical microscopy, and scanning electron microscopy coupled with X-ray energy dispersive spectrometry-EDS. The oxidation state of the adsorbed As species was determined by X-ray absorption near edge structure spectroscopy. The results demonstrate that the presence of naturally occurring Mn oxides promotes the effective oxidation of As (III) to As(V). Also, the Mn minerals show a significant uptake of both the trivalent and pentavalent As species. This study demonstrates that the combined influences of As(III) depletion by oxidation and adsorption on a natural oxide sample consisting of Mn minerals and Fe oxides may effectively contribute to the reduction the As concentration in waters.

Phyllosilicate mineralogy is key to understanding hydrothermal processes within accepted epithermal deposit models but little information has been published about the mineral chemistry of epithermal deposits. X-ray diffraction, optical and electronic microscopy (scanning and transmitted), electron microprobe, and Fourier transform infrared spectroscopy were used in this work to study phyllosilicates in the Palai-Islica Au-Cu epithermal, volcanic-hosted deposit, in order to link phyllosilicate mineralogy and mineral chemistry to ore genesis. Different phyllosilicate assemblages are characteristic of two types of mineralization, and related hydrothermal alteration. Chlorite and mica appear in polymetallic quartz veins with sulfides, and in the related chloritic and sericitic hydrothermal alteration. These minerals have notable textural and chemical differences (i.e. Fe/(Fe+Mg), Si and Al in chlorite and illitic and phengitic components in mica) amongst veins and altered rocks, revealing different genetic conditions. These chemical features also distinguish propylitic and regional, non ore-related, low-temperature alteration. Hot hydrothermal fluids of near-neutral pH are responsible for vein mineralization and alteration. Illite, interstratified illite-smectite, kaolinite, and pyrophyllite are characteristic, with a distribution pattern by zones, of the intermediate argillic and advanced argillic alteration around areas of silicification. In the latter, native gold appears associated with interstratified illite-smectite, suggesting a relatively low-temperature formation. Hot, low-pH fluids are responsible for this mineralization and alteration assemblage. The present study contributes to epithermal models showing the co-existence of two different alteration styles in the same hydrothermal system.

One day in 2018, I arrived at Playwrights Horizons in New York City excited to see a new play by Lindsey Ferrentino called This Flat Earth. I did not know much about the story aside from the fact that it had teenage actors playing teenager characters, but I quickly realized that it was about two teens trying to make sense of a recent mass shooting event as their school. The most striking part of this experience was watching Ella Kennedy Davis playing a thirteen-year-old white girl named Julie who takes out her anger, grief, and confusion about this senseless violence on those around her. Davis spent much of the play on the emotional limits of anguish, screaming, crying, and shaking to the point where she continued to do so throughout the curtain call. Both my discomfort with the actor's obvious distress, and my genuine dislike for the whiny, sad, one-dimensional role—whose main characteristic is her ignorance of previous school shootings—were enough to distract me from the play itself. But what created this distancing effect? I first thought of Bert O. States's phenomenological observation that children onstage often break our illusion of the theatrical world, but I noted that my phenomenological response was distinctly different from what I feel when I see children acting onstage. Instead of wondering if the actor understood the play she was in, I instead feared she understood all too well.

The Carrera de Indias, considered as a set of circuits connecting Hispanic America to world markets, does not appear as a “monopoly” reserved solely for the Spanish merchants of Cadiz, but rather as a complex commercial system, structured into three autonomous segments, each of them dominated by a mercantile corporation, more or less formalized. In the central part, which linked the two shores of the Atlantic, the merchants registered in the Consulado of the Indies of Cadiz (cargadores) obviously dominated the market. However, these were in turn dominated by the merchants from the consulates of Mexico and Lima in the inland trade (comercio de tierra adentro), which linked the great American ports and fairs with the markets of the interior of the continent, and by the foreign merchants of Cadiz, structured into “nations,” in the exchanges that linked the Andalusian port with the rest of Europe and the world. Thus, the beneficiaries of the Spanish colonial trade in the second half of the eighteenth century were neither only cargadores, nor foreign “smugglers” enjoying the weakness of the Spanish empire as the historiography of the Carrera de Indias has traditionally postulated, but those three groups of traders.

After highlighting this singular structure of colonial trade in the Spanish Atlantic, we will consider the different institutional and relational factors that could explain it. Obviously, it is because the different groups of actors involved in these exchanges had a specific social, relational, cultural, and institutional capital that they had a comparative advantage over their rivals in certain segments of the Carrera de Indias circuits, and that they were able to obtain the dominant position that we observe.

The interaction of cytochromes (heme proteins) with mineral surfaces is important from an environmental perspective (e.g. heavy metal remediation and reductive dehalogenation reactions), for designing biosensors and bioanalytical systems, and for emerging photovoltaic applications. In addition, the cytochrome studied here shares properties with some cytochromes from Fe-reducing bacteria and its general behavior sheds light on how other cytochromes might behave during Fe(III) reduction. The objectives of this study were to characterize the direct electrochemistry and sorption mechanism of horse heart ferricytochrome c (a mitochondrial cytochrome referred to as Hcc) on hematite surfaces as a function of pH, time of sorption and ionic strength. Hcc sorption on hematite mainly occurs between pH 8 and 10, the pH range in which hematite surfaces and Hcc are oppositely charged. Calculated net attractive forces correspond closely with the pH range of peak sorption, suggesting that sorption is mainly electrostatically controlled. Hcc sorption with ionic strength is consistent with this conclusion. The pH-dependent conformation of Hcc sorbed on hematite appears to be different from that in solution as indicated by UV-visible spectroscopy and its more negative reduction potential compared to native Hcc. Sorption kinetics were rapid and pH-independent across the pH range 3–10 with slow conformational changes occurring at >60 h. Our results suggest that the electrostatic attraction of the cytochrome towards the surface orient the cytochrome for favorable electron transfer between the heme group of the cytochrome and hematite.

Nontronite is a significant component of commercially important nickel laterite ores. Its behavior during high-pressure acid leaching of such ores may have an impact upon the efficiency of the process. The present study was conducted in order to further investigate the response of this material during high-pressure acid leaching. In situ synchrotron powder X-ray diffraction data were collected from a number of nontronite samples during hydration and leaching reactions at ambient and elevated temperatures. The present study followed previous high-pressure acid-leaching studies of nontronite where unexpected contraction and expansion behavior of the clay was observed by means of in situ X-ray diffraction. In the earlier studies the data sets only extended to ~20 Å so that when the nontronite expanded to greater than 19.5 Å (hydrated) the main 001 peak was only partially visible in the observed d-spacing range. The aim of the current work was to collect similar in situ diffraction data over a greater d-spacing range to observe more fully the movement of the main 001 reflection in order to better understand the changes taking place. This work was undertaken at the powder diffraction beamline of the Australian Synchrotron which was configured such that an upper d-spacing limit of ~34.5 Å could be achieved. Suggestions arising out of the previous work were confirmed along with additional information from testing of samples from the Source Clays Repository of The ClayMinerals Society. These results also show contradictory behavior of clays with the layer charge distributed over tetrahedral and octahedral sheets.

A diapiric intrusion of clays in the Carlentini Formation (Tortonian) was discovered in a quarry at S. Demetrio High (Hyblean Plateau, Sicily, Italy). Seven clay samples were analyzed by different analytical methods, including X-ray powder diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy, to determine the composition and mechanism of formation (sedimentary vs. hydrothermal) of these clays. Ferric saponite, carbonates (calcite and traces of ankerite), quartz, pyrite, and zeolites (phillipsite and harmotome) were detected using XRD and FTIR. This mineral assemblage, dominated by Fe-rich saponite, and the abundance of light rare-earth elements (LREE), Eu, fluid-mobile elements (FME > 10 × primordial mantle: Li, Be, B, As, Sb, Pb, U, Ba, Sr, Cs), and other incompatible elements (Zr = 169 ppm, Nb = 46 ppm, Th = 11 ppm, on average) imply that S. Demetrio clays precipitated from a mixture of hot Si-rich hydrothermal fluids (350–400°C) and cold seawater. The evidence is in accord with the affinity of clays for hydrothermally modified mafic and ultramafic rocks, forming the Hyblean lower crust, based on multi-element comparisons, and on the occurrence of trace amounts of chrysotile 2Mc1 and sepiolite. The association of long-chain aliphatic-aromatic hydrocarbons (intensity ratios I2927/I2957 > 0.5) with hydrothermal clays, the lack of fossils, and the similarity of the IR absorption bands with those of organic compounds detected previously in some metasomatized Hyblean gabbroic xenoliths suggest a possible abiogenic origin of hydrocarbons via a Fischer-Tropsch-type reaction. The S. Demetrio clay diapir was emplaced at shallow crustal levels in the Late Miocene as a consequence of the interaction, at a greater depth, of an uprising basalt magma and the products of an early, serpentinite-hosted hydrothermal system.

A new method has been developed for quantifying smectite abundance by sorbing polyvinylpyrrolidone (PVP) on smectite particles dispersed in aqueous solution. The sorption density of PVP-55K on a wide range of smectites, illites and kaolinites is ∼0.99 mg/m2, which corresponds to ∼0.72 g of PVP-55K per gram of montmorillonite. Polyvinylpyrrolidone sorption on smectites is independent of layer charge and solution pH. PVP sorption on SiO2, Fe2O3 and ZnO normalized to the BET surface area is similar to the sorption densities on smectites. γ-Al2O3, amorphous Al(OH)3 and gibbsite have no PVP sorption over a wide range of pH, and sorption of PVP by organics is minimal. The insensitivity of PVP sorption densities to mineral layer charge, solution pH and mineral surface charge indicates that PVP sorption is not localized at charged sites, but is controlled by more broadly distributed sorption mechanisms such as Van der Waals’ interactions and/or hydrogen bonding. Smectites have very large surface areas when dispersed as single unit-cell-thick particles (∼725 m2/g) and usually dominate the total surface areas of natural samples in which smectites are present. In this case, smectite abundance is directly proportional to PVP sorption. In some cases, however, the accurate quantification of smectite abundance by PVP sorption may require minor corrections for PVP uptake by other phases, principally illite and kaolinite. Quantitative XRD can be combined with PVP uptake measurements to uniquely determine the smectite concentration in such samples.

Maghemite (γ-Fe2O3) is a ferrimagnetic Fe oxide commonly found in tropical and subtropical soils, especially in the topsoil where it is usually a product of burning. Isomorphic substitution (IS) of the Fe in maghemite by different metals (mainly Al3+) can modify its mineralogical and chemical attributes, and these modifications may be important to understanding the formation and properties of this mineral in soils and sediments. The objective of this work was to evaluate the crystallochemical alterations of synthetic, Al-substituted maghemites prepared by the precipitation of magnetites from alkaline aqueous media containing FeSO4·7H2O with increasing amounts of Al2(SO4)3·7H2O to obtain hypothetical Al3+ for Fe3+ substitutions ranging from 0.0 to 40.0 mol %. The Al-substituted magnetites were washed and dried, and then heated to 250ºC for 4 h to form yellowish red maghemites that were characterized by total chemical analysis, X-ray diffraction, specific surface area (SSA), mass-specific magnetic susceptibility, infrared spectroscopy, transmission electronic microscopy, and color. Increasing Al3+ substitution to an experimental maximum of 15.9 mol % decreased both the a0 dimension of the cubic unit cell (a0 = 0.8339 − 396.157 × 10−16 Al, r2 = 0.99) and the mean crystallite dimension (MCD = 76.4–3.15Al, r2 = 0.79) of the maghemites. With the decrease in MCD came a more yellowish color, an increase in SSA, and a decrease in crystallinity as measured through extraction of the samples with acid ammonium oxalate. The mass-specific magnetic susceptibility of the maghemites increased with Al3+ substitution up to 5.3 mol % and then decreased with further replacement of Fe by Al. Solid-phase aluminum in excess of 16 mol % substitution appeared to occur as a separate, poorly crystalline phase that was X-ray amorphous.

Hematite (α-Fe2O3) possesses distinct spectral properties which facilitate its identification in mineral mixtures. This paper reports the relationships between the visible diffuse reflectance (DR) spectrum and the color and crystal properties of a group of 81 natural and synthetic hematites. The visible DR spectra for powdered hematite samples diluted to 4 wt.% with BaSO4 white standard were recorded and used to calculate the corresponding Munsell colors. The second derivative of the Kubelka-Munk function of the DR was used to estimate the position and intensity of the main absorption bands, which occurred at ∼435, ∼485 and ∼545 nm. The Munsell hue ranged from 9.5P to 5.3YR and was negatively correlated with the position of the ∼545 nm band, so it became yellower as the band shifted to shorter wavelengths (higher energies). The Munsell value, which ranged from 4.9 to 8.6, and chroma, which ranged from 1.4 to 8.3, were negatively and positively correlated, respectively, with the intensity of the ∼545 nm band, the position of which exhibited a weak negative correlation with the degree of Al substitution (x). The position and intensity of this band also exhibited a weak negative correlation with the specific surface area (SSA); both, however, were uncorrelated with domain shape as measured by the ratio between the X-ray mean coherence lengths (MCLs) in the [110] and [104] directions. The properties of the ∼435 and ∼485 nm bands were unrelated to x, SSA or MCL110/MCL104. The negative relationship between the position of the ∼545 nm band and x does not support the assignment of this band to the 2(6A1) → 2(4T1g(4G)) electron pair transition (EPT), which relates to the to Fe3+−Fe3+ magnetic coupling between face-sharing octahedra. The ∼485 nm band might reflect a ‘goethitic’ structural component in Fe-defective hematites as it appears at the same wavelength as the hypothetical EPT related to Fe3+−Fe3+ magnetic coupling between edge-sharing octahedra in goethite (α-FeOOH).

Imogolite is usually formed by means of a three-step process involving the use of large amounts of water with long crystallization times and low yields, preventing large-scale synthesis. These drawbacks can be overcome by synthesis in the presence of fluoride, an approach which has been demonstrated to be suitable for the synthesis of other phyllosilicates. In the present study, the nature of the Al and Si sources, the Al/Si molar ratio, the volume of H2O for the redispersion of the gel after desalination, the F/Si molar ratio, as well as the crystallization temperature and time have been varied to investigate their role in the crystallization of imogolite. The structural properties of the as-synthesized samples were characterized by X-ray diffraction, infrared spectroscopy, and 29Si, 27Al, and 19F magic angle spinning nuclear magnetic resonance spectroscopy. The results show that the imogolite nanotubes can be prepared with high yields (>55%) from AlCl3·6H2O and Na4SiO4 aqueous solutions with an Al/Si molar ratio of 2.5, addition of HF for a F/Si molar ratio of 0.1–0.2, and 4 days of crystallization at 98°C.

The mechanism by which the anionic polymers interact with platelets of 2:1 clay minerals is not fully understood. The objective of the present study was to evaluate the effect of the electric field associated with the basal and edge surfaces of the clay minerals on the adsorption of anionic polymers. Two negatively charged polymers, PAM90 and ACC86, of the same molecular weig ht (2 × 105 g mol−1) but with different degrees of hydrolysis (90 and 20%, respectively), were used. The effect of pH (6, 10), NaCl concentration (0, 10 mmolC L−1) and clay particle size on PAM90 adsorption by pyrophyllite and the effect of NaCl concentration on the adsorption of these polymers by Na-montmorillonite in aqueous suspensions were studied. Adsorption of PAM90 on pyrophyllite was greater at pH 6 than at pH 10 and greater in 10 mmol L−1 NaCl than in distilled water. Adsorption of PAM90 on pyrophyllite increased with decreasing particle size. On pyrophyllite the high-charge-density PAM90 was adsorbed to a greater extent than the low-charge-density ACC86; by contrast, ACC86 adsorption was greater than that of PAM90 on Na-montmorillonite. These results were attributed to the repulsive forces which develop between the negatively charged extended-chain polymer and the extended negative electric field associated with the basal surfaces, around the Na-montmorillonite platelets. The results may suggest that the edge surfaces play a major role in PAM adsorption.

Disposal facilities in deep geological formations are considered to be a possible solution for long-term management of high-level nuclear waste (HLW). The design of the repository generally consists of a multiple-barrier system including Fe-based canisters and a clay backfill material. The Fe-clay system will undergo a thermal gradient in time and space, the heat source being the HLW inside the canisters. In the present paper, the effect of a thermal gradient in space on Fe-smectite interactions was investigated. For this purpose, a tube-in-tube experimental device was developed and an 80–300ºC thermal gradient was applied to a mixture of MX80 bentonite, metallic Fe (powder and plate), magnetite, and fluid over periods of 1 to 10 months. Transformed and newly formed clay minerals were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Mössbauer spectroscopy. The main mineralogical transformations were similar to those described for batch experiments: smectite was destabilized into an Fe-enriched trioctahedral smectite and Fe-serpentine or chlorite as a function of the experimental conditions. Newly formed clay was observed all along the walls of the gold tube. Their crystal chemistry was clearly different from the clays observed in the hot and cold part of the tubes. The thermal diffusion of elements was also observed, especially that of Mg, which migrated toward the hottest parts of the tubes. In the end, the thermal gradient affected the redox equilibria; more reduced conditions were observed in the hotter parts of the tubes.

Limited information is available on microporosity in soils. A study was undertaken to investigate the micropore characteristics of four soil samples, with different particle-size distributions, and four natural silicate clay minerals. Specific surface area and the differential micropore-size distribution were taken into account to characterize the microstructure of the soils and clays. The micropore-size distributions showed a maximum contribution to the total microporosity by pores having an effective pore radius of ∼20 Å, thus indicating that that category of pore contributes more than others to the total microporosity of the system. For both soils and clays a good exponential correlation was found between the maximum contribution to the microporosity and their specific surface area. A linear relationship was also found between the microporosity of the soils and their clay content. It has been concluded that the micropore system formed by 20 Å pores is mainly located in the clay fraction of the soil, and contributes significantly to defining some of the most notable physicochemical properties of soils and clays.